Drive method and drive device for a hybrid vehicle

Abstract

A drive device for a hybrid vehicle, which has a first driven axle and a second driven axle, including: a first motor/generator unit, which is connected to the first driven axle; an internal combustion engine unit, which is connected in a rotationally fixed fashion to a differential/transmission unit which is connected to the rear axle; a second motor/generator unit, which is connected in a rotationally fixed fashion to the differential/transmission unit, parallel to the internal combustion engine unit; a clutch unit, which is designed to disconnect and connect a force flux between the differential/transmission unit and the second driven axle; and a control unit, which actuates the clutch unit, the internal combustion engine unit, the first motor/generator unit and the second motor/generator unit as a function of predefined operating states.

The invention claimed is: 
     
       1. A drive device for a hybrid vehicle, which has a first driven axle and a second driven axle, comprising:
 a first motor/generator unit, which is connected to the first driven axle; 
 an internal combustion engine unit, which is connected in a rotationally fixed fashion to a differential/transmission unit which is connected to the second driven axle; 
 a second motor/generator unit, which is connected in a rotationally fixed fashion to the differential/transmission unit, parallel to the internal combustion engine unit; 
 a clutch unit, which is configured to disconnect and connect a force flux between the differential/transmission unit and the second driven axle; and 
 a control unit, which actuates the clutch unit, the internal combustion engine unit, the first motor/generator unit and the second motor/generator unit as a function of predefined operating states. 
 
     
     
       2. The drive device as claimed in  claim 1 , wherein the first motor/generator unit comprises two electric machines which are each connected to wheels of the first driven axle. 
     
     
       3. The drive device as claimed in  claim 1 , wherein the clutch unit is embodied as a frictionally engaging clutch which is configured to be shifted by the control unit. 
     
     
       4. The drive device as claimed in  claim 1 , wherein the first motor/generator unit and the second motor/generator unit are each configured to be controlled by the control unit in a motor mode or in a generator mode. 
     
     
       5. A drive method for a hybrid vehicle, which has a first driven axle and a second driven axle, a first motor/generator unit which is connected to the first driven axle and a differential/transmission unit which is connected to the second driven axle and which is connected to an internal combustion engine unit and to a second motor/generator unit, said method comprising:
 using a clutch unit to disconnect and connect a force flux between the differential/transmission unit and the second driven axle; and 
 using the control unit to actuate the clutch unit, the internal combustion engine unit, the first motor/generator unit and the second motor/generator unit as a function of predefined operating states. 
 
     
     
       6. The drive method as claimed in  claim 5 , wherein operating states of the drive device are activated by the control unit,
 wherein, in a first operating state, when the internal combustion engine unit is switched on, the first motor/generator unit and the second motor/generator unit are operated by motor; 
 wherein, in a second operating state, when the internal combustion engine unit is switched on, the first motor/generator unit is operated as a generator and the second motor/generator unit is operated as a generator or motor; 
 wherein, in a third operating state, when the internal combustion engine unit is switched off, the first motor/generator unit is operated as a motor and the second motor/generator unit is operated as a generator; 
 wherein, in a fourth operating state, when the internal combustion engine unit is switched on, the first motor/generator unit is operated as a motor and the second motor/generator unit is operated as a generator. 
 
     
     
       7. The drive method as claimed in  claim 6 , wherein the drive method has a further operating state which is activated by the control unit, wherein, when the internal combustion engine unit is switched off, the first motor/generator unit and the second motor/generator unit are operated as generators. 
     
     
       8. The drive method as claimed in  claim 5 , wherein the drive method has a further operating state which is activated by the control unit, wherein, when the internal combustion engine unit is switched off, the first motor/generator unit is operated as a motor. 
     
     
       9. The drive method as claimed in  claim 5 , wherein the drive method has a further operating state which is activated by the control unit, wherein, when the internal combustion engine unit starts, the first motor/generator unit and the second motor/generator unit are operated as motors. 
     
     
       10. The drive method as claimed in  claim 5 , wherein the drive method has a further operating state, which is activated by the control unit, wherein, when the internal combustion engine unit is switched on, the first motor/generator unit is operated as a motor and the second motor/generator unit is operated as a motor or as a generator. 
     
     
       11. The drive method as claimed in  claim 5 , wherein the drive method has a first changeover of operating state, which permits a changeover from an operating state with a switched-off internal combustion engine unit to an operating state with a switched-on internal combustion engine unit, by operating the second motor/generator unit as a motor. 
     
     
       12. The drive method as claimed in  claim 11 , wherein the drive method has a second changeover of operating state, which permits a changeover from an operating state with a switched-off internal combustion engine unit to an operating state with a switched-on internal combustion engine unit by entraining the internal combustion engine unit.